SIRTF Update - August 25, 2003

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov

Veronica McGregor (818) 354-9452
Jet Propulsion Laboratory, Pasadena, Calif.

News Release: 2003-118
August 25, 2003

Space Infrared Telescope Facility Mission Status

Following last night's picture-perfect launch, NASA's Space Infrared
Telescope Facility is positioned exactly where ground controllers want
it to be, trailing behind Earth as it orbits the Sun. The spacecraft
is working and communicating well with the Deep Space Network
antennas, receiving commands and returning telemetry data.

The spacecraft entered a stand-by mode when its star tracker did not
lock on to its planned targets within the expected 60 seconds. This
possibility was anticipated, and therefore engineers had already
prepared a contingency plan, which has been activated. The star
tracker did subsequently lock onto its targets and engineers believe
the delay is likely due to higher-than-expected background noise
levels.

The operations team is also investigating two thrusters that are
somewhat warmer than expected, and some inconsistent telemetry points
from the cryogenic telescope assembly.

"These types of anomalies are expected in a space observatory of this
size and complexity," said David Gallagher, Space Infrared Telescope
Facility project manager at NASA's Jet Propulsion Laboratory,
Pasadena, Calif. "The team is ecstatic with the successful launch and
the way the mission is progressing overall. We eagerly await the start
of science observations."

The next milestone will occur when the telescope's dust cover is
opened in five days. This event occurs during the mission's two-month
in-orbit checkout, which will be followed by a one-month science
verification phase. After that, the science mission will begin a quest
to unlock some of the oldest cosmic mysteries, and to look for
possible planetary construction zones in discs around other stars.
JPL, a division of the California Institute of Technology in Pasadena,
manages the Space Infrared Telescope Facility for NASA's Office of
Space Science, Washington, D.C. Further information about the Space
Infrared Telescope Facility is available at

http://sirtf.caltech.edu/

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